Sunday, May 8, 2011

sats and sats

       Sats and Sats.

       Last week ``Beyond Moon and Mars (BMM)'' reported in The Times of India, that satellites had played a key role in helping US forces to locate the hideout of Osama Bin Laden at Abottabad in Pakistan. They were American military satellites and worked flawlessly.

       This was a success story of space technology.

       But, a week later we hear that satellites because of technological limitations failed to spot the wreckage of the ill-fated Pawan Hans helicopter in which Arunachal Pradesh CM, Dorjee Khandu, was travelling.

       They were Isro's remote sensing satellites, and the ones which scanned the area were Kalpana-1, Resourcesat 1 and 2, Risat-2 and the Canadian Space Agency's Radarsat-2. The helicopter crashed on April 30 killing the CM and Isro's help was saught on May 1.

       Interestingly, the frank admission about the mission's failure does not come from any ill informed mediaperson or social activist, but none other than the Hyderabad-based National Remote Sensing Centre (NRSC), a part of Isro, which processes images from the remote sensing satellites and distributes them to users..

      An announcement made by NRSC on Sunday states: ``The area where the accident occured was a rough mountaineous Himalayan terrain covered with a thick forest. Persistent cloudy conditions and incessant bad weather limited the use of optical remote sensing data.''

      It says: ``An attempt was made to use mircowave remote sensing data which can penetrate clouds and quickly image large areas in all weather conditions.''  But, this too proved unsuccessful because microwave sensors were sidelooking. Worse they did not have the capability to penetrate dense vegetation. Additionally, microwave data of short wavelength do not penetrate dense vegetation.

     What is the message?  Since these satellites did not quite serve their purpose---though they have performed exceptionally well on other occasions---Isro officials told BMM that the space agency needs to design and develop more radar imaging satellites. At present there is just a single satellite in this category---Risat-2. The launch of Risat-1 is slated for later this year.

      This failure comes close on the heels of the spectacular success of the PSLV last week which partially lifted Isro out of its crisis. But again the set back with regards to the satellites' inability to locate the wreckage of the helicopter will revive memories of some of the other disasters faced by Isro, especially the two failures of the Geo Synchronous Satellite Launch Vehicle (GSLV).

      But, then in space technology failures are inevitable and are viewed as a learning experience.

      It is often stated that 26X11 led to quick design and development of Risat-2. Maybe the unfortunate experience at Arunachal Pradesh will result in the making of more powerful radar imaging satellites.

      Indian remote sensing satellites have set a world record and their ability has even been acknowledged by international users.

      Let them retain this tradition.

      We are proud of them.  

       An announcement made by

No comments:

Post a Comment